Instead of storing each model in a separate file, MetaEdit+ uses an object database to store user data. This enables efficient reuse of data between models, but does entail some differences in saving changes compared with simpler file-based tools. Rather than saving files, MetaEdit+ uses a transaction-based approach to committing and abandoning changes.

Starting MetaEdit+ and logging into the repository starts a transaction. All changes you make to your design data are part of the transaction, and are not propagated into the repository immediately. To store the changes permanently, you need to explicitly commit the transaction. Commit will save the changes to the repository and start a new transaction for a new set of changes. It is also possible to abandon the transaction, which means canceling the changes and returning to the previously committed state.

To commit your current transaction, press the Commit button on the Launcher toolbar (see Figure 1–10), or select Repository | Commit from the Launcher’s menu. To abandon, press the Abandon button on the toolbar (see Figure 1–10) or select Repository | Abandon....

Note that in a repository-based application, you must treat all files of the repository as an indivisible whole. You cannot copy a few files to another repository, or between versions of the same repository; instead, see the export and import facilities in Section 5.3.